Not quite the same but I have an iPhone 3GS active right now running on the SIM from my iPhone 7 (nano SIM to standard SIM adapter). It's on AT&T but it's also unlocked and it was on Straight Talk previously. Still works great!
I'd think as long as you've got EDGE out there it'd be able to activate and if it's unlocked. Tons of tools out there for that, though they are on the older side most still work on macOS or Windows.